Hi @GavandKaty,
Welcome to the Bunnings Workshop community, it is wonderful to have you with us.
How tall is the retaining wall on the boundary of your block?
I ask because typically retaining walls over 1m in height require submission of plans to your local council for approval. This is because retaining walls of this height are retaining considerable weight and they need to be confident that they are suitably engineered to retain this weight. If you are planning to tie a colorbond fence into this retaining wall, I suspect it would need to be considered as part of this submission.
Unfortunately, I am not aware of a suitable method for attaching a colorbond fence to prepoured concrete through the use of a bracket or something similar. If this is the solution you were hoping for, then you may have to speak with a fencing contractor for their advice, as it is not a typical installation. There are brackets like these Pioneer 187 x 6mm 0.58m Galvanised Steel Fence Bracket, although they are used with
If not all of the besser bricks have been core filled, you might be able to set the posts inside the cells of the besser bricks, then core fill them to set the posts in place. This would be the best solution if the cells in the besser bricks line up well with where you need the posts to sit.
Let me know what you think.
Jacob
